Feed mechanism for sewing-machines.



H. K. HOHMANN.

FEED MECHANISM FOR SEWING MACHINES.

APPLlCATiON FILED MAR. 22. 1913.

1,204,873.. Patented Nov. 14,- 1916.

E Em l J mlllllll R. K. HOHMANN.

FEED MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR.22.*19I3. I

Patented N 0v. 14, 1916.

4 SHEETS-SHEET 2.

, 4 .K :W% P |IIPI H lll l mm R. K. HOHMANN;

FEED MECHANISM FOR SEWINGMACHINES.

APPLICATION'HLED MAR. 22. m3.

Patented'Nov. 14, 1916.

4 SHEETS-SHEET 3.

I Inn-mum Ill oovooo oo o q R. K. HOHMANN.

FEED MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 22. I913.

Patented Nov. 14, 1916.

. 4 SHEETS-SHEET 4.

RICHARD K. HOI-IMANN, OF SAN QIEGO, CALIFORNIA.

FEED MECHANISM FOR SEVTING-MAOHINES.

Application filed March 22 To all whom it may concern Be it known that I, RICHARD K. Horr- MANN, a citizen of the United States, and resident of San Diego, county of San Diego, State of California, have invented certain new and useful Improvements in Feed Mechanism for Sewing-Machines, of which the following is a specification.

This invention relates to mechanism for feeding the cloth in sewing machines and is shown applied to a high speed rotary hook machine. other features of which are cov ered by another application which I am filing herewith.

The invention includes means for raising and lowering the feed member to bring it into contact with the cloth and separate means for moving the member backward and forward to cause the feed, and also means whereby the extent of the forward. and backward movement can be changed without interfering with theaction of the other parts of the mechanism.

The novel features of the invention will be apparent from the following description, taken in connection with the drawings.

In the drawings, Figure 1 is an end elevation of the working parts of the machine embodying my invention; Fig. 2 is a bottom plan view; Fig. 3 is a side elevation partly broken a *ay to show the operating mechanism; Fig. 4 is a vertical section on the line l l of Fig. 3.

In these drawings I have shown the work plate 1 of a sewing machine having the usual hollow vertical standard 2 carrying the hollow horizontal arm which has on its forward end. the head 3 in which the needle bar 1- and presser foot bar 5 are mounted. The needle bar is operated by the rotating shaft 6 which has power applied to it from any suitable source through the pulley 7 The presser foot bar 5 has means for adjusting the pressure on it, which consists of the screw threaded member 8 which is adapted to be turned to raise and lower it exerting greater or less pressure on the spring 9. The shaft 10 carrying the rotary hook at its forward end is driven by a belt 11 passing over a pulley on the shaft 6, and in this case it is unnecessary to describe in detail the rotary hook, the bobbin holder, and the means for passing the thread around the bobbin since these features constitute the subject- Speoification of Letters Patent.

change the extent of the movement.

Patented Nov. 14, 1916.

, 1913. Serial No. 756,258.

matter of the companion case above mentioned.

The feed mechanism is mounted below the work plate and includes the feed arm 50 adapted to project through the plate slightly and having on its upper surface the ratchet teeth 51. This feed bar in the present machine is operated from the continuously rotating shaft 6 in the standard above the work plate by connections independent of the means by which the revolving hook shaft 10 is operated. The arm 50 is pivoted at one end so that it will move with the arm 52 rigidly secured to the rock shaft 53 and since the arm 52 occupies a substantially vertical position its rocking movement will give to the arm 50 a horizontal back and forth movement. The rock shaft 53 is given its oscillating movement by a certain link mechanism shown in Fig. l, and that mechanism is capable of such adjustment as to An arm 5% is rigidly secured to the shaft 53 and has pivoted to its upper end a link 55 which in turn is pivotally connected to the link which is pivoted at its other end to the rod 57 which is adapted to be held rigidly in adjusted positions. The arms 55 and 56 are at an angle to each other, forming a toggle lever and at their point of connection the vertical rod 61 is pivotally secured andextends up to the rotary shaft 6. This rod (31 has on its upper end a bearing surrounding a cam on the shaft 6 whereby the rod is given an upward and a downward movement on each revolution of the shaft, the shape of the cam being such as to time the movements in such a way as to properly feed the cloth. The rod 57 has on its end a thumb screw 58 for adjustably clamping it in position and this rod is adapted to move bodily around the segment 59 in the slot 60 and as it moves the angle formed between links and 56 is changed. Since the rod 61 is connected at the joint of the toggle and'moves transversely thereof, a fixed movement of the rod will cause different movements of the arm 54 and a different rotation of the shaft 53 in accordance with the angle which the link 55 forms with the link 56. It is apparent therefore that the extent of the back and forth movement of the feed arm 50 can be varied at will by changing the position of the rod 57.

It is necessar to give the feed arm an up and down movement as well as a longitudinal movement in order to properly feed the cloth, and I have devised a separate and distiuct means for giving this up and down move1nent. This means includes the rock shaft 62 below the work plate of the machine, this rock shaft being given a fixed oscillating movement by means of the arm 63 andthe rod 64 reciprocated vertically by a camon the shaft 6. The rock shaft 62 has .ticular means shown for connecting the arm 55 with the feed arm 50 consists of a rod 67 fitting in a socket in the arm 65 and a socket in the arm 66 which is connected to the feed arm 50. A spring 68 tends'to pull the arms (55 and '66: together and they are held in their spaced relation by the rod 67 This construction permits the uniform oscillations of the rod 62 to give to the feed arm a uniform up and down movement properly V timed and at the same time permits the arm 50 to inoveback and forth horizontally in accordance with the throw of the shaft 53.

The change in the stitch due to the change in tllGjQOSltlOll of the rod 57 can be made easily and quickly by the operator of the machine whether the machine is in operation or is idle, and 1t Wlll be observed that the operating rod is above the work table easily accessible to the operator.

While I have shown the invention applied to amachine. of the type covered in my co- Copies of this patent may be obtained for pending application, it will be understood that in its prior aspects the invention is not limited to use with this particular machine and that it is not confined to the details of construction.

Havingthus described the invention, what is claimed is:

The con'ibination with the work plate of a sewing machine, a hollow vertical standard thereon, a rotatable shaft carried at the upper end of said standard, a cloth feeding member adapted to project through said plate, a rock shaft below said plate for re ciprccating said cloth feeding member, a link arm for rocking said rock shaft, a second link arm pivoted to the end of the first mentioned link arm and forn'iing a toggle lever therewith, an adjustable pivotal support for one end of said second link arm, said adjustable support extending out through said standard and above said plate, a vertically reciprocating rod in said standard operated by said rotatable shaft and pivotally connected at its lower end to the toggle lever at the point where the link arms thereof are connected together, a second rock shaft below said plate, a rock arm mounted on said second rock shaft, means for connecting said rock arm to the cloth feeding member, and a second vertically reciprocating rod in said standard operated by said rotatable shaft and having means at its lower end for connecting it to said second rock shaft to rock the latter whereby the cloth feeding member is raised and lowered as it is reciprocated.

In testimony whereof I aflix my signature in presence of two witnesses.

RICHARD K. I'IOHLNIANN.

lVitnesses WILLIAM L. PIERCE, JACOB Baorr.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. V 

